Tyre sizes on a 622/17 rim

[nicey74]

Hi there, I am running a touring bike with a child seat on the back. I am pretty chunky and with my daughter on it I would like to do more to spread the shocks to the frame (steel). I'd like to put a fatter/wider tire on it and find the sizing on the shop websites a bit baffling. Does anyone know what width tire or can recommend one for heavy loaded touring to me.

It looks like I have a fair bit of clearance to the frame

Much appreciated

Richard

 

[the_mikey]

For a 622x17 rim, you can run700x25, 700x28, maybe 700x30 or maybe bigger, but check the frame and more importantly the brake calipers will accomodate the tyre adequately.

 

[Ajax Bay]

Rule of thumb is that you can sensibly run a tyre up to twice the internal rim width (frame clearance allowing).

 

[Ajax Bay]

Your rim may have its size marked on it eg 21-622. The '21' is the internal rim width and 622 is the ETRTO (international measurement standard) for the notional wheel diameter (in mm) - add 2 x 39mm (height of tyre) and you get to the 'old' 700 nomenclature.
Lack of clearance through calipers (rim brakes) for an inflated tyre has easy (if slightly irritating) workarounds.
A 'pretty chunky' person with a 15kg child on the back will need a 42mm wide rear tyre up at 80psi (wild estimates on tyre load made) which is likely the maximum rating for the tyre. Better data = more specific advice. HTH